On 7/15/21 7:04 PM, Mark Gray wrote:
> On 15/07/2021 15:29, Dumitru Ceara wrote:
>> On 7/15/21 3:54 PM, Mark Gray wrote:
>>> On 15/07/2021 14:16, Mark Michelson wrote:
>>>> Hi Mark,
>>
>> Hi Mark, Mark,
>>
>>>>
>>>> I'm a bit curious about this change. Does the removal of the protocol 
>>>> from the match mean that traffic that is not of the protocol specified 
>>>> in the load balancer will be ct_dnat()'ed? Does that constitute 
>>>> unexpected behavior?
>>>>
>>>
>>> Yes, this is the case. It's a tradeoff between number of flows and
>>> reirculations but thinking about it again, it may be better to have more
>>> flows. I will create a v2.
>>>
>>
>> Unless we match on proto *and* L4 port I don't think it's worth adding
>> per proto flows.  Assuming a TCP load balancer, all TCP traffic with
>> destination VIP will still be ct_dnat()'ed, even if the TCP destination
>> port is not the one defined in the load balancer VIP.
>>
>> On the other hand, using the same VIP for multiple ports is probably a
>> common use case so if we add the L4 port to the match the number of
>> logical flows might increase significantly.
> 
> I don't think we can match on L4 port AFAIK, this could cause misses
> with fragmented packets (which is the whole point of the defrag table).

You're right, sorry about the noise.

> 
> I guess it depends on the use case as that will determine the number of
> vips (which will generate a certain number of flows) and the traffic
> pattern (which will determine the average number of ct_dnat()s). In a
> system with a handful of VIPs for TCP traffic but mostly hosting UDP
> traffic, it may be better to do as Mark M. suggests.
> 
> The number of flows may not be that high as we only add one flow per
> protocol rather than one per port. So I guess in the worst case, this
> could be 4x the number of load balancer VIPs associated with the logical
> router.
> 

Ok, it doesn't sound that bad indeed.

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